This invention pertains generally to missile control systems and particularly to a system of such type used to interdict a guided missile in flight toward a target.
It has been known for some time that so-called "repeater" jammers carried on an expendable decoy may effectively be employed to protect a target against a radar-controlled guided missile. Briefly, such a jammer includes a responder which produces signals that are, substantially, replicates of the echo signals from a target to be protected except that the amplitude, or apparent origin, or some other significant characteristic of such replicates differ from the echo signals from the target to be protected. As a result, the guidance system on the attacking missile is caused to track the decoy rather than the target to be protected.
It is apparent that, if successful diversion of a radar-controlled guided missile from a target to be protected is to be effected, "tracking" on the decoy must be maintained until the guided missile cannot be maneuvered to impact on the target intended to be protected. The requisite deception is, however, difficult to achieve because guidance systems for attacking missiles are now designed to distinguish between echo signals from a target and signals from a decoy whenever the signals from the latter differ to an appreciable degree from a predetermined norm. That is to say, if any one of the many parameters (such as power level, pulse shape, angle, or range rate, to mention a few) of signals from a decoy differs substantially from what may be expected from a target, a modern guidance system will soon recognize the presence of the decoy. In all probability, then, sufficient time will still be available for the attacking missile to be guided to impact on the target desired to be protected.